The present application generally relates to buckles and latch plates for seat belts and more specifically to a locking latch plate and cooperating buckle.
More specifically the present invention relates to a manually activated cam mechanism which locks the lap belt portion of the seat belt (also sometimes referred to as "web or webbing") preventing it from tightening about the occupant. The cam mechanism is automatically released when the release button of the buckle is depressed.
The present invention will be described in the context of a three-point restraint system, however, this is not a limitation of the present invention. A typical three-point seat belt system includes a retractor, fastened to the vehicle frame or seat, a web guide (web support, D-ring) mounted to the B-pillar (or to the seat), a latch plate, having a tongue portion for insertion into a buckle. The latch plate is often slidable on the shoulder belt portion of the seat belt. The buckle can be mounted to the vehicle floor or to the seat. Upon inserting the tongue into the buckle the seat belt is divided into a shoulder belt portion and a lap belt portion to protect the occupant. As is known in the art, seat belt retractors include a rewind spring which provides a bias force to rewind excess slack in the seat belt upon a spool of the retractor. As the vehicle hits large holes and bumps in the road, it and the occupant begin to bounce. When the occupant bounces onto the seat a transient amount of slack in the seat belt is created as the seat is compressed (by the occupant). This response is more predominant in certain off-the-road vehicles which encounter very rough roadways. The rewind bias spring of the retractor eliminates this slack and attempts to pull the seat belt taut (to cinch) about the upper torso and lap of the occupant. However, when the occupant rebounds off the seat or when the vehicle stops bouncing the occupant may find that the lap belt has slid through the latch plate and is now uncomfortably tightened about his or her body necessitating the removal of the latch plate from the buckle to re-fit the seat belt about his/her body.
Accordingly, the present invention comprises: a manually activated seat belt device comprising: a latch plate comprising: a tongue including first locking means for lockingly engaging a cooperating part of a seat belt buckle. The latch plate additionally includes a rear or second part, having a seat belt web clamping surface adjacent to a belt receiving opening. The rear part includes walls extending about opposite sides of the belt receiving opening and a yoke which is slidably received upon the latch plate above the opening and slidable relative to the walls of the second or rear part. The yoke also includes a clamping bar. The seat belt is inserted through the belt receiving opening between the belt clamping surface and the clamping bar. The latch plate also includes a clamp or lock initiating mechanism manually movable from a cinching or free position to a locking position and includes a cam surface which when moved to its locking or cinching position urges the rear bar toward the clamping surface to thereby clamp or lock the seat belt therebetween and first means cooperable with a seat belt buckle to maintain the mechanism in its locking position and for releasing same when the button of the seat belt buckle is depressed.
It is an object of the present invention to provide a latch plate that can be manually locked upon the seat belt to prevent the seat belt from being excessively tightened about an occupant. A further object of the present invention is to provide a seat belt buckle with a release button to deactivate the locked seat belt.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.